Radio and wireless protocols that allow a single wireless communications transceiver to seamlessly transfer communications between different base stations have greatly expanded the usefulness of mobile communications. Applications such as cellular phone systems allow a mobile radio transceiver to seamlessly transfer a communications session from one base station to another without interruption of the communications session. Such a transfer is usually performed as a mobile transceiver moves from one cell to another.
The multiple base stations of these systems are generally assigned a transmitting frequency on which to transmit an identifying transmission that may also contain other data. The RF frequencies used for these transmissions are generally restricted to a small set that can be efficiently monitored by a mobile receiver that is part of a mobile transceiver. A mobile receiver is able to monitor these base station transmissions and identify transmissions from base stations that are sufficiently close to the mobile receiver to allow effective reception. The base stations that are close enough to a mobile receiver so as to allow effective reception communications are referred to as “neighbor stations.” In cellular telephone systems, these transceivers are referred to as “neighbor cells.” Mobile receivers and transceivers periodically attempt to receive transmissions from neighbor stations and then measure the received signal quality of each received transmission. The mobile receiver is then able to determine, by identifying the received signal with the highest signal quality, the neighboring base station that is the best candidate for radio communications. Signal quality measurements include determining a signal to noise, carrier to interference (C/I) ratio, and/or Bit Error Rate (BER) for the received signal. The neighboring base station that transmits the signal that is received with the highest signal quality is presumed to also be the best base station with which the mobile transceiver can engage in two-way wireless communications. Once this highest quality base station is determined, it becomes the “serving cell” and the mobile receiver begins to decode control channel information from this cell according to a certain schedule. The other surrounding base stations are then categorized as “neighbor cells” whose “signal quality”, or C/I, is periodically monitored according to a separate schedule. This allows the mobile receiver to switch over, or “hand off” to the neighbor cell with the strongest C/I when the serving cell C/I drops below a certain threshold relative to the neighbor cells.
The area near a cellular telephone base station transceiver in which mobile transceivers can effectively communicate with that base station is often referred to as a cell. As the mobile transceiver moves among the cells associated with different base stations, the base station with the highest quality signal is subject to change. Various radio mobility management algorithms are used in different mobile radio applications to monitor the neighboring stations in order to determine with which base station to communicate. Some of these protocols generally perform a cell monitoring process that monitors transmissions from neighboring cells, determines the transmission that is received with the highest signal quality, and selects the cell that corresponds to the transmission that is received with the highest quality for communications. This cell monitoring process is performed periodically according to the requirements of the particular protocol.
This periodic monitoring of transmissions from neighbor stations unfortunately consumes transceiver resources and power. This is a particularly significant consumption of resources and power when a mobile transceiver is operated in a standby mode that can last for hours or days while the mobile transceiver is not engaged in an active communications session. The conventional mobile transceiver continues to monitor neighbor stations at the same periodic monitoring rate to determine the best station with which to communicate, whether the mobile transceiver is stationary or moving.
Therefore a need exists to overcome the problems with the prior art as discussed above.